Business Segments (Tables)

6 Months Ended

Jun. 30, 2020

Segment Reporting [Abstract]

Financial Data for Continuing Operation for Company's Reportable Business Segments

The following table displays selected financial data for the Company’s reportable business segments. Total revenues, as presented on the consolidated statements of earnings and comprehensive earnings, exclude intersegment revenues which represent sales from one segment to another segment, which are eliminated in consolidation. Prior-year segment information has been reclassified to conform to the reporting structure change described in Note 1.

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2020			2019			2020			2019
	(Dollars in Millions)
Total revenues:
Mid-America Group	$	392.3		$	414.5		$	653.1		$	662.6
Southeast Group		142.2			137.0			263.4			256.3
West Group		682.5			651.7			1,193.1			1,149.2
Total Building Materials Business		1,217.0			1,203.2			2,109.6			2,068.1
Magnesia Specialties		53.6			76.3			119.3			150.3
Total	$	1,270.6		$	1,279.5		$	2,228.9		$	2,218.4
Products and services revenues:
Mid-America Group	$	362.9		$	381.9		$	603.9		$	611.5
Southeast Group		136.8			132.0			253.7			247.4
West Group		640.9			611.8			1,114.1			1,076.0
Total Building Materials Business		1,140.6			1,125.7			1,971.7			1,934.9
Magnesia Specialties		48.9			70.4			108.8			139.5
Total	$	1,189.5		$	1,196.1		$	2,080.5		$	2,074.4
Earnings (Loss) from operations:
Mid-America Group	$	136.2		$	141.3		$	157.0		$	171.9
Southeast Group		33.7			32.7			47.7			53.8
West Group		133.2			110.6			155.9			130.9
Total Building Materials Business		303.1			284.6			360.6			356.6
Magnesia Specialties		13.2			25.2			34.9			47.9
Corporate		(9.9	)		(23.9	)		(31.3	)		(49.4	)
Total	$	306.4		$	285.9		$	364.2		$	355.1